What is a ‘beam’ and a ‘draft’ anyway?

So we are now 2 wrecks into our series but I deemed it a good idea to explain some common nautical terms regarding ships and shipwrecks.

All too common that a boat skipper or dive leader will be giving a briefing which to a wreck head is perfectly understandable, but for the common layman makes no sense whatsoever…indeed I think these folk derive a certain pleasure from the confused looks they receive when they talk about triple expansion engines and davits….

Plus I believe a wreck dive is all the more special when you know what you are looking at, for example what at first glance may appear as a mundane, barnacle encrusted piece of metal may to the educated observer be a lot more fascinating….

So to start with I will give some general ships’ terms and in future posts we will go into more specialised areas such as engines, weaponry and more…

Length: Come on guys, let’s not be silly…

Beam: It’s width at the widest point, the more narrow it is when compared to length generally the faster the ship was designed to go but with a loss of stability.

Draft: The distance from the waterline to the bottom of the hull. AKA: how much of the ship is physically in the water. Knowing this will allow the crew to determine the minimum depth of waterway the ship can safely navigate.

Displacement: The technically correct version of the ship’s weight. Actually refers to the weight of water the ship displaces.

Laid down: The date construction on the ship began. Derives from the traditional days of ship building when the length of the keel was ‘laid down’ first and then the rest of ship built around it.

Keel: Essentially the ‘spine’ of the vessel. A large beam that runs the length of the ship and forms a large part of structural integrity.

Launched: Pretty obvious…

Commissioned: The date the ship enters service, when launched they are often empty shells but are fitted out once on the water to allow space in the shipyard for new constructions.

Bow: Pointy end

Stern: Blunt end

Port: Left hand side when facing the bow

Starboard: Right hand side when facing the bow

Forward: Facing or travelling from the stern to the bow

Aft: Facing or travelling from bow to the stern

Davit: The structure used to lower items over the side of the ship. Mostly in our case will be life boat davits.

Complement: Crew

Anchor: Heavy object thrown over the side to prevent the ship from moving when at rest.

Winches: Mechanical device to ‘let out’ or ‘pull in’ rope or cable. (such as that attached to the anchor)

Capstans: Similar to the above. A vertically axled device to apply pressure to a rope or a cable, although a winch traditionally stores the rope/cable on a drum.


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